Module 1 Introduction To Pharmacology Flashcards
What is pharmacology?
The study of biological effects of chemicals
What are drugs?
Chemicals that are introduced into the body with the intent to cause a change
What is pharmacotherapeutics and what is its focus?
- The use of drugs to treat, prevent, and diagnose disease
- focus is on:
1.) drugs effect on the body
2.) body’s response to the drug
What is a controlled substance?
Any drug with an abuse potential (physical or psychological dependence)
DEA (drug enforcement agency)
Monitors the prescription, distribution, storage, and use of controlled substance drugs in an attempt to decrease substance abuse
Schedule l (c-1)
Define and examples
- No currently accepted medical use and a high potential for abuse
- marijuana, heroin, mescaline, lysergic acid diethylamide (LSD), methylenedioxymethamphetamine(MDMA)
Schedule 2 (c-2)
Define and examples
- High potential for abuse
- possible severe psychological or physical dependence
- fentanyl, hydromorphone, methadone, morphine, methamphetamine
Schedule 3 (c-3)
- define and examples
- Moderate to low potential for physical and psychological dependence
- still potential for abuse
- anabolic steroids, hydrocodone
Schedule 4 (c-4)
- define and examples
- Low potential for abuse and dependence
- Valium, Xanax, Darvon, phentermine
Schedule 5 (c-5)
- define and examples
-lowest potential for abuse
- Limited quantities of certain narcotics
- antidiarrheals, antitussives, analgesics
Drug use during pregnancy
- No drug is “safe”
- benefit outweighs the risk
Teratogenicity
- Adverse effects on the fetus
Old categories of drug risk classification
A, B, C, D, X
New risk classification
- Pregnancy
- lactation
- reproductive potential
Brand name drug characteristics (5)
- Name given by drug company once the drug is approved by the FDA
- companies research, test, and manufacture drugs
- more expensive
- drug formula is patented
- Insurance companies may not cover brand medications
Generic name drug characteristics(6)
- Original name given to the drug when it was submitted to the FDA for approval
- companies only manufacture drugs
- significantly less expensive
- same active ingredients
-Most states require generic drugs - generic drugs are safe
What are prescription drugs?
- Requires an order/prescription by a licensed provider
What are OTC drugs?
- Over-the-counter drugs
- available without a prescription for self-treatment
- are safe when taken as directed
- behind the pharmacy counter
OTC drug concerns(4)
- mask signs and symptoms of underlying disease
- can interact with Rx drugs and interfere with drug therapy
- serious overdoses can occur if not taken as directed
- patients often do not consider these drugs, so they do not report taking them
What are pharmacodynamics?
- How the drug affects the body
-The d in dynamics stands for drug (memory technique)
What are pharmacokinetics?
- How the body acts on the drug
What are the 4 mechanisms of action (MOA)
- Receptor action
- physical action
- act on other chemicals in the body
- enzyme/metabolic action
Define receptor action
-act on receptor sites located on the cell membrane
- agonist or antagonist
- agonist: birds to receptor site to increase or stimulate normal response
-Antagonist: binds to the receptor site to depress, block, or slow normal response
Define physical action
- Changes the physical properties of cells or body fluids
- damage the cell wall or alter pH
Define “act on other chemicals in the body”
- Creating chemical reactions
Define enzyme/metabolic action?
- Processes in the body requiring multiple steps to have an effect
- drugs can interfere with one of the steps by stoping, delaying, or speeding it up
Define “timing of drug action”
-onset, peak, duration
Define “critical concentration”
- Amount of drug needed to cause a therapeutic effect
Define “loading dose”
- Higher dose then that normally used for treatment
- recommended dosing schedule is followed once critical concentration is reached
Define “dynamic equilibrium”
- The actual drug level in a person’s body
Define “therapeutic index”
- Ratio comparing the blood concentration at which a drug becomestoxic with the concentrationat which the drug is effective
List the steps in which the body processes drugs
1.)absorption
2.)distribution
3.)metabolism (biotransformation)
4.)excretion
When does the process of absorption start and end?
- Starts when the drug enters the body
- ends when the drug reaches the circulating fluids and tissues
Types
of absorption
1.)passive diffusion
2.)active transport
3.)filtration
What are the main factors that influence absorption?
- Route
- solubility
-Tissue perfusion - ionization
- size
What is the fastest route for absorption?
- IM/IV
What allows the best solubility?
- Water and lipid soluble best
Tissue perfusion necessary for absorption
- tissue performance needs to be adequate (when supply meets demand)
Ionization needed for absorption
- No charge is the best ionization for absorption
What is the best size of molecules to absorb?
- The smaller the faster they will be absorbed
Movement of drug distribution
- The movement of drug through systemic circulation to the body’s tissues
- depends on the same factors as absorption
What are the components of distribution?
- Solubility (water and fat)
- ionization (no charge)
- tissue perfusion (adequate)
-protein-binding - blood-brain barrier(BBB)
- placenta and breast milk
Protein-binding with distribution
- Difficult for drug to cross the cell membrane
- Only “free” particles cause a therapeutic effect
-Tightly bound versus loosely bound
-Competition for protein-binding sites - Most drugs are bound to proteins in order to travel through the bloodstream
-The more tightly a drug is bound to the protein,the longer it takes for the drug particles to get free to enter the cell membrane - If it can’t get free from the protein binding sitethen it can’t work on the tissues.
-“Loose bound” means that they act faster and are excreted faster